yokoi 1.2.3 © 2002-2005 by Turku PET Centre

Calculates the distribution volume DV or DVR (=BP+1) using multiple-time graphical analysis (MTGA) for reversible PET ligands (Yokoi plot) (1). Parameters: 1) Tissue TAC file 2) Name of plasma file OR reference region name in TAC file 3-4) Start and end times for linear fit 5) Result file (existing file is overwritten) [6) Filename for plot data and fitted lines (optional) ] Options: -N SDs are not saved. -mid[=<y|n>] Mid frame times are used (y) or not used (n, default) even if frame start and end times are available. Least-squares line fit method can be selected with following options: -C Traditional regression model -M Median of two-point slopes and intercepts (Cornish-Bowden) -P Perpendicular regression model (2) -R Iterative method (York 1966, Lybanon 1984, Reed 1992); default If tissue file contains weights, the iterative method (-R) is weighted. With other fitting methods the weights are not used. With options -C and -R program can automatically find the linear plot range, if fit start time is set to zero. e.g. yokoi ut2345.dat ut2345ap.dat 10 60 ut2345.res or yokoi ut2345.dft cer 20 60 ut2345.res ut2345yplot.htm References: 1. Yokoi T, Iida H, Itoh H, Kanno I. A new graphic plot analysis for cerebral blood flow and partition coefficient with iodine-123- iodoamphetamine and dynamic SPECT validation studies using oxygen-15-water and PET. J Nucl Med. 1993; 34(3): 498-505. 2. Varga J & Szabo Z. Modified regression model for the Logan plot. J Cereb Blood Flow Metab 2002; 22:240-244. See also: logan, fitk4, lhsoldv, patlak, rescoll Keywords: DFT, modelling, distribution volume, Yokoi plot